9 Bright Ideas on How to Build a Sunroom on a Budget

You can already picture it—sunny mornings with coffee and a book without having to step outside. But how do you build a sunroom on a budget? With the cost of a sunroom ranging anywhere from $5,000 to $140,000, here are nine tips for keeping sunroom costs on the lower end of the spectrum.

9 Tips for Building a Sunroom on a Budget

So, what is a sunroom? In short, the design is exactly as it sounds. Often featuring windows from the floor to the ceiling—and sometimes even overhead—a sunroom welcomes in as many rays as possible while still remaining closed from the elements. Depending on the style you’re going for, sunroom design bridges the gap between screened-in ideas and an enclosed solarium. 

Here are nine tips for keeping sunroom costs under control before and during your build.

1. Transform an Existing Space

Budget-friendly sunroom design costs often involve transforming an existing room, enclosed porch, or even a deck. You'll pay an average of $5,000 to $50,000 to build a sunroom on an existing foundation. Keep in mind that adding a sunroom on a deck will require significant fortifications, but you can still save money on land preparation and clearing. An existing space will also likely have access to your home's wiring and heating system—two of the highest costs when building a four-season sunroom.

2. Opt for a Three-Season Sunroom

Early in the process, you'll need to choose between a three-season and four-season sunroom. A four-season sunroom requires insulation, electrical wiring, and access to the HVAC system to help you through the colder months. Three-season sunrooms, on the other hand, can include as many or as few of these features as it likes. 

Three-season sunrooms cost between $10,000 and $40,000 on average, whereas building a four-season sunroom can cost up to $80,000.

3. Aim for a Garden Room or Atrium

Simpler versions of the solarium are garden rooms—AKA conservatories—or atriums. Garden rooms are smaller spaces with minimal ventilation that create a humid greenhouse that’s ideal for plants. The design is simpler and a bit less finished compared to other styles. Atriums are also comparatively cost-friendly, as they often involve only transforming the ceiling of a room into windows instead of the surrounding walls.

4. Keep Square Footage Small

As is the case with so many home design projects, the size of the build often has the largest say in your bottom line. Building a sunroom costs between $150 and $300 per square foot on average. With some creativity, you can create a diminutive space as small as 50 square feet and still install a small seating area, table, and plenty of plants.

5. Install a Prefab Sunroom

Here's where you can really tap into some cost savings. Prefab sunroom kits can cost as little as $5,000 before delivery and installation. And speaking of installation, some prefab kits are even relatively DIY-friendly depending on their size and how they connect to your home. The kits will come in larger pre-constructed pieces so that they easily and more quickly compile into a frequently used design.

6. Consider DIYable Finishes

All your sunroom ideas will take shape once you begin designing the interior of your room. Like most home additions, you need to think about:

• Flooring

• Window style

• Wall color

• Electrical outlets

• Fans and heaters

• Lighting fixtures

• Furnishings

• Exterior siding

Early on in your design process, differentiate which finishes you can safely install on your own and which are best left to the professionals. For example, glass installation, wiring, and some styles of flooring require contractors. The decision will either come down to permits and local building codes or the cost of potentially making an error during DIY installation.

However, you can learn how to install vinyl floors, particularly those that lock and click into place, potentially saving hundreds in installation costs. And depending on whether the wiring already exists or needs to be installed—in which case, you should leave it for a professional— adding a ceiling fan or replacing a lighting fixture by yourself are also options.

7. Get Creative with Your HVAC

If you do opt for a four-season room, you could spend in the tens of thousands for the heating system alone. Some potentially less-expensive options include extending your ductwork or installing a mini-split HVAC mount to the sunroom. If you already have a ductless mini-split system, the cost to add a new mini-split mount runs from $400 to $1,000. 

You can think even simpler in your three-season room if you want to bundle up in the winter. Add a space heater appropriate for the size of the room, particularly if you opt for outlets but skip the HVAC system.

8. Consider Your Financing Options

Staying within your sunroom budget requires building a budget in the first place. Once you have your initial numbers, consider the long-term costs of different home addition financing options. For example, iff you opt for a HELOC loan against the equity of your home, it may take longer to receive the cash than other options. Personal loans and credit cards are more immediate, but interest rates tend to run higher, potentially throwing off your budget in the long run.

9. Don't Skip the Planning Stage

If you're months out from breaking ground on your sunroom, good for you! Planning the details of your sunroom far in advance is the best way to keep costs under control. Research at least three local sunroom contractors near you to compare costs, timelines, and contract details. 

It's also important to scour photos of your ideas in the sunroom to provide a clear picture to your contractor of your vision. Once you nail down the structural design, zoom in further and research individual flooring, window, wall, and furniture options that are worth the investment.

Sunrooms On Any Budget

When you're plotting out how to build a sunroom on a budget, how much are we really talking? The vast price range doesn't clear up a lot of questions, particularly because there are so many directions you can take your design. Here are some budget ranges and details to picture it.

Under $10,000

Small sunrooms under 60 square feet often fall into this range, which is more than enough room to host a few friends over a cup of tea. You can also include prefab sunrooms of many styles in the sub-$10,000 range, particularly if you're building a conservatory or atrium. Keep the cost of exterior siding low by opting for vinyl, wood, or aluminum.

Under $20,000

Opt for a small custom or larger prefabricated three-season sunroom for less than $20,000. In this range, you can stretch your design further into tile flooring options, ceiling fans, and stylish lighting fixtures. For smaller sunrooms, you can also fortify porches and add foundations for new additions.

Under $60,000

Here's where you break into the mid-range options for four-season sunrooms. Prepare the land and add a foundation for a new home addition. Consider larger floorplans up to 400 square feet and consider extending a mini-split HVAC system to your porch. You can still cut costs for projects of this size by installing finishes on your own and revamping any surrounding gardens and landscaping on the outside of your sunroom.

Under $80,000

As we get into the higher end of the sunroom budget, consider the long-term cost savings on adding insulation and extending your current HVAC to the space. While sunrooms don't always add value to your home as far as livable square footage, they will certainly boost the curb appeal and value of having a unique home design. Most sunrooms under $80,000 also include floor-to-ceiling windows, stone siding, and your pick of furnishings.